Clutch/Tranny Problem

[SeanC]

Hey guys,

I just had my T56 rebuilt and just got it back in this weekend with a replacement clutch and pressure plate. Everything seemed to be working great, but now, every once in a while it grinds a little bit going into gear (I have only had this happen with 2nd and 4th for some reason). I was starting to think that it was my mistake and that I didn't disengage the clutch all the way, but I started really making sure the clutch pedal was to the floor before I shifted and it still is grinding every once in awhile. I'm guessing that my clutch isn't disengaging all the way? I don't know if its a coincidence, but it seems like it mostly happens when I first start driving the car after it sits for a while. I'm so frustrated because I thought I had my car back for good, but now I feel like i'm ruining my brand new transmission! Any help would greatly be appreciated. Thank you!

[RAF7789]

-taking a shot in the dark-

could it be a clutch fluid bleeding issue?

[Jeff_in_Atl]

What fluid are you using? I am starting to think that synthetic fluid for a manual transmission is not a good idea. I keep hearing too many complaints about grinding gear with it. If you think about it, it makes sense. Synthetic fluid reduces the friction compared to conventional fluid. Synchronizers require friction for them to work. If you reduce the friction you reduce the effectiveness of the synchronizers.

[SeanC]

I didn't think it would be a bleeding issue because I never disconnected the master cylinder/slave cylinder line. Before doing the job I didn't have this problem. I never replaced my slave cylinder, but am starting to think I should have...

Jeff, I am using an oil made by the company I got my transmission rebuilt by (Rockland Standard Gear). It is specially made for the T-56 and I can't imagine it would be giving me this problem... If anyone has heard of the company, I am using their "Tranzilla" fluid.

I drove the car this morning and it was grinding going into gear when I first started driving it (it was pretty cold out). It seems like as soon as the car warms up, the problem disappears and it doesn't grind. I guess i'm going to stop driving it until I get the problem straightened out, because I can't afford to ruin my transmission... Thank you very much for the help so far guys!

[Jeff_in_Atl]

Well when a fluid gets colder it doesn't flow as well. I'm going to say it hs something to do with the fluid. I don't think it is a clutch problem or it would do it all the time.

http://www.rsgear.com/lubricants.asp
According to the chart they use RSG-400+ fluid in the T56. I can't find anything about it.

http://www.rsgear.com/articles/2000_08.pdf
Here they say to use ATF only.

They have a lot of stuff in the technical article.

[SeanC]

I called up the transmission shop to see if they had any suggestions and he keeps telling me that it is "improper clutch release". I questioned how this was possible considering that if i'm sitting still, I can put it into any gear without it grinding, but he claimed that the pressure plate gives more pressure on the clutch when it warms up (does this make any sense?). He said I can change the fluid to ATF to see if it fixes the problem, but he also said that I have to eventually add his fluid in because of the carbon fiber syncro rings he put in (once again, does this make any sense?)

When I put it back together, I did not buy a new flywheel, but got mine resurfaced instead (it was in good shape to begin with). He claims that I should have absolutely not done this and he has never heard of a T56 working with a resurfaced flywheel. Is this true?

I'm sooo frustrated right now...What do you guys think? I'm planning on changing to ATF tomorrow to see if it fixes the problem. It really sounds like the fluid to me considering that after 3 minutes of driving it, it shifts fine. Thanks for the help!

[Jeff_in_Atl]

When I put it back together, I did not buy a new flywheel, but got mine resurfaced instead (it was in good shape to begin with). He claims that I should have absolutely not done this and he has never heard of a T56 working with a resurfaced flywheel. Is this true?

It depends on how they resurfaced it. If they ground it on a blanchard grinder (circular marks overlapping each other) that can make it chatter really badly. If they turned it on a lathe (concentric rings from the center out) it should be OK.

But that isn't going to make a difference for your symptoms.

[Jeff_in_Atl]

I'm sooo frustrated right now...What do you guys think? I'm planning on changing to ATF tomorrow to see if it fixes the problem. It really sounds like the fluid to me considering that after 3 minutes of driving it, it shifts fine. Thanks for the help!

At this point I would do the following.
1. change the fluid to what GM recommends which is Dextron 3 ATF.
If that doesn't fix it,
2. Replace the clutch/slave cylinder. I think the whole thing (which is inseparable on a LT1) runs about $125.
If that doesn't fix it call them and ask them what to do.